ISLAMABAD, Pakistan --Khalid Shaikh Mohammed is one of Osama bin Laden's most trusted associates and his name is linked to most of al Qaeda's recent operations.

Mohammed is said to have been involved in planning al Qaeda 'spectaculars' from Yemen to Bali to New York.

And his arrest could provide information on the whereabouts of other terrorist members, possibly including bin Laden.

"He is a very, very crafty operator and the next best thing to Osama bin Laden and Ayman Al-Zawahiri," said CNN correspondent Mike Boettcher, referring to al Qaeda's two most senior leaders.

Born in Kuwait -- either on March 1, 1964 or April 14, 1965 -- Mohammed's al Qaeda roots run deep and wide

In 1996, he was indicted in New York for his alleged involvement in a Philippines-based plot to blow up 12 U.S.-bound commercial airliners in 48 hours. The indictment has no legal bearing right now, U.S. government officials said; the priority is to interrogate him.

"Daniel Pearl was going in search of the al Qaeda network that was operational in Karachi, and it was at the instruction of Khalid Shaikh Mohammed that Daniel Pearl was killed."

Mohammed has also been linked to the bombing of the USS Cole in 2000; Richard Reid's foiled 2001 attempt to blow up an airliner with a shoe bomb; and most recently, the bombings at the El Ghriba synagogue, in Djerba, Tunisia and the Bali bombings last year.

The synagogue bombings were the first al Qaeda attacks outside Afghanistan after September 11, 2001.

Mohammed, who holds Pakistani passport, was almost picked up last week in Quetta, Pakistan. Officials there arrested one suspected al Qaeda operative, but Mohammed escaped, according to highly placed Pakistan officials.

Officials then used the captured suspect to track Mohammed to a house in the middle-class suburb of Rawalpindi, nine miles southeast of Islamabad and home of Ahmed Abdul Qadoos, a member of Pakistan's largest religious political party, Jamaat Islami.

September 11 boast

STATEMENT

White House reaction to the detention of Khalid Shaikh Mohammed:"The United States commends Pakistani and U.S. authorities on the completion of a successful joint operation which resulted in the detention of several al Al Qaida operatives, including Khalid Shaikh Mohammed."Khalid Shaikh Mohammed is one of Usama Bin Laden 's most senior and significant lieutenants, a key Al Qaida planner and the mastermind of the September 11th attacks. He is known to have been centrally involved in plotting by Al Qaida terrorists since September 11th, 2001--including plots to launch attacks within the United States."Khalid Shaikh Mohammed is on the FBI's list of most wanted terrorists, and has been under U.S. indictment since 1996 for the Manila air conspiracy, a plot to bomb a series of U.S. civilian airliners."

Last September, Yosri Fouda, a reporter for the Arab-language Al-Jazeera television network, said he interviewed Mohammed while making a documentary for the one-year anniversary of the September 11 attacks.

Fouda said Mohammed introduced himself as the head of the al Qaeda military committee. He told Fouda that he attended the meeting, complete with details, in which the decision was made to strike at America inside America.

Coalition intelligence confirmed Mohammed's presence at the meeting.

Mohammed's indictment and federal arrest warrant provide details of how Mohammed operated within al Qaeda. The documents were unsealed after Ramzi Yousef -- Mohammed's nephew -- was sentenced in 1998 for his role in the 1996 airliner plot.

The indictment says Yousef rented an apartment in Manila, where he and Mohammed -- who used the name Salem Ali -- lived and mixed chemicals for explosives. They also had "modified timing devices," according to the indictments.

The airliner plot, nicknamed "Bojinka", which roughly translates to "explosion" in Serbo-Croatian, was uncovered in January 1995 when the "bomb factory" apartment caught fire.

Authorities searching Yousef's laptop computer found detailed plans to blow up the airliners -- including flight numbers and schedules and bomb-making formulas.

Also in the computer was a communication signed by "Khalid Shaikh" and a letter that threatened to attack American targets "in response to the financial, political and military assistance given to the Jewish state in the occupied land of Palestine by the American government."

The letter, apparently written by Mohammed and his associates, also threatened to assassinate the president of the Philippines, attack aircraft, or even launch a biochemical attack if one of their co-conspirators was not released from custody.

Yousef was caught in Pakistan in February 1995. Mohammed was indicted on seven counts of terror conspiracy for his role in the plot.

U.S. and Canadian intelligence documents based on the interrogation of Mohammed Mansour Jabarah, an al Qaeda operative who reported to Mohammed, show the level of detail and planning involved in an al Qaeda attack.

Mohammed sent Jabarah from Pakistan to southeast Asia on September 10, 2001, according to the documents.

Mohammed sent him to lay the groundwork for suicide truck bombing runs on U.S. and British embassies in Singapore, Indonesia, and the Philippines on September 11, 2002 -- the one-year anniversary of the attacks, according to the documents.

The plan was foiled after the breakup of a terrorist cell in Singapore. Jabarah was arrested last March, shortly after the cell was broken up, and is in U.S. custody.